Evaluation of the progeny populations from crosses between a resistant sweet corn inbred (Zea mays L.) and 3 susceptible inbreds indicated that the variation for partial resistance to corn leaf rust (Puccinia sorghi Schw.) depended on the parents used. Heritability estimates were high with both additive and dominance gene effects important in character expression. Epistasis was shown to influence rust reaction in at least one cross. The ability to improve partial resistance in 2 sweet corn populations was demonstrated by 3 methods of selection.